The goal of the proposed project is to use antibodies recognizing portions of the human Blym oncogene translation product to facilitate its characterization. Synthetic peptides composed of amino acids from the predicted Blym amino acid sequence will be used as immunogens to generate rabbit heterosera and murine monoclonal antibodies reactive with both the peptides and the native Blym protein. Initial screening for anti-peptide reactivity will be accomplished using the enzyme linked immunoabsorbant assays (ELISA), and subsequent assessment of reactivity with the native protein will include immunoprecipitation, immunoblotting, fluorescence microscopy and fluorescence activated cell sorter analysis. Antibodies reactive with the Blym protein will be used to determine its subcellular location, cell cycle expression and association with other cellular proteins, and to evaluate quantitative and qualitative differences in protein expression in normal and neoplastic cells. These antibodies will also facilitate the characterization of Blym protein expression in leukemias and lymphomas of B and non-B cell origin and help define the protein's role in both normal cellular differentiation and lymphomagenesis.